This is one more illustration that you can make models that show any result.

-- indication that climate change processes may have varying impacts on different areas of the globe. ---

And how much did that enlightened statement cost?

To me, that more of a "well, duh!"

Based on all the studies that have come out, global warming apparently is the cause of warming, cooling, drought, floods, glaciers melting, ice packs forming, dandruff, gingivitis, mold, poor satellite reception, bovine flatulence, Geraldo Rivera and the designated hitter rule. Truly a horrible deforming of nature by human beings (specifically in the central lattitudes of the North American continent, which is the nexus of evil and selfishness in the world).

This is one more illustration that you can make models that show any result.

Particularly since, in this case, not all of the variables are known, and of those that ARE known, few firm figures are available.
One simply plugs in whatever values best fit one's notion about what the outcome should be.

For instance, it's not at all impossible that we're at the beginning of a new ice age, despite the (possibly) rising temps.

And what a lot of people fail to take into account is that this planet has feedback mechanisms built into its systems that have worked for millions of years, and that we haven't found all of them because some only appear in extreme circumstances (like in reaction to an ice age). When your model shows a linear trend, or one that goes way off scale, or some other nonsense, the first question you should be asking is what got left out. or what you did wrong. But thanks to politicized science, those questions are shouted down.

Most of these models, if run given conditions in 1850 or 1900, would show conditions nothing like the real 2000. If you can't predict the past and the present, then you shouldn't be predicting the future, either.

Michael - It's worse than that, there's no theoretical mechanism to constrain the number of parameters or the relationships between them. Even the "greenhouse effect" is not based on any radiative transfer calculations, because greenhouse physics would give an effect two orders of magnitude too small.

PJ:

Something else I have always wondered about the greenhouse gas effect, but haven't seen mentioned anywhere.

Since greenhouse gases block Earth's Infrared (IR) wavelength radiation emissions into space, presumably CO2 et al do the same thing in reverse--increasingly prevening the sun's radiation in the IR band from getting to the Earth in the first place.

Jeff: You're right, CO2 blocks infrared going both ways. But since most of the sun's output is in the visible, while most of the earth's output is in the infrared, this is much more significant for the earth's radiation.

Now, clouds are great at not just blocking, but reflecting visible light. Which is why clouds are about 100 times more important than CO2 (a 1% increase in cloud cover cancels out a 100% increase in CO2). If I had to identify just where the sleight-of-hand is taking place in this scam, it would be in how the models handle cloud cover.

"What could be more quintessentially human than our routine overestimations of our impact on the planet?"

Indeed. It calls to mind an obscene joke (warning for the faint-hearted, read no further):

What's the definition of arrogance?
An ant humping an elephant, yelling, "Take it all, beeyatch!"

Earth is the elephant; enviromentalists are the ant.

The cleaner version being: "Sorry, did I hurt you?" Used it yesterday for Chirac.

Bob:

Thanks.

I'm sure your answer is completely correct, but just out of curiousity, I should track down somewhere the power spectrum of the Sun's emissions v. the Earth's.